Micrometer control



Feb. 29, 1944. G. A. BATE MICROMETER CONTROL Filed Aug. 50, 1941Patented Feb. 29, 1944 MICROMETER CONTROL George A. Bate, RidgefieldPark, N. J., assignor to The Lummus Company', New York, N. Y., acorporation of Delaware Application August 30, 1941, Serial No. 409,003

(Cl. 'lll-424.8)

3 Claims.

This invention relates to improvements in variable volume controlapparatus and more particularly to a volume control of micrometricaccuracy for proportioning mechanisms such as positive displacementrotary pumps and the like.

In many industrial fields proportioning devices are used to control theamount or the magnitude` of the various components or materials that areintroduced to blending equipment or the like. In the blending oflubricating oils, for example, it is frequently necessary to mixproportioned quantities of as many as four or five principal streams ofdifferent lubricating oil stocks and one lor more minor streams ofadditives such as pour point depressants or the like. The quantities ofall of these streams must be controlled within very small limits ofaccuracy in order to efficiently produce the desired blended product.

One form of apparatus which has proved especially satisfactory in thelubricating oil blending field and to which my invention applies isshown in the patent to Cornell, No. 2,109,331, issued February 22, 1938.In this construction the proportioning devices are positive displacementrotary pumps, and the capacity or volume of each pump is controlled by ahandwheel having a micrometer type of housing that indicates the degreeof volume control.

lIn the commercial operation of such proportioning devices it has beencustomary to install two or more large size pumps for the principal oilstreams and one or more fractional sized pumps for the minor additivestreams. This arrangement has proved expensive, however, not onlybecause of the additional cost of the differentsize units that arerequired in small numbers only but also because of the special mountingsrequired and the added expense of calibration. Standardization ispreferable if the results are equal.

The principal object of my invention is to pro'- vide a standardizedsize of proportioning device having a volume control variable betweenzero and unity and having a single indicating scale so that uniformreadings on a plurality of such devices give proportional percentageflows based on the scale volume settings.

A more specific object of my invention is to provide an intermediatescrew coupling in combination with a micrometer screw control for avariable colume control apparatus so that the control device ispositively moved within the range of the micrometer screw control onlythat percentage of the full range of the latter as determined by thecharacteristics of the intermediate screw coupling.

More specifically, it is an object of my invention to provide amicrometer screw control for the volume of a positive displacementrotary pump, which screw control is so arranged with respect to thevolume control pump plunger that, by the substitution of one couplingbetween the screw control and the pump plunger for another, it ispossible to have the same adjustment of the micrometer screw controlindicate different proportional differences of opening of the pumpplunger control, the differences being whole numbers of one with respectto the other.

A more specific object of my invention is to provide an adapter to beinterconnected between a micrometer screw adjustment and a volumecontrol device, which adapter includes a screw threaded housing and anintermediate screw interconnected to the micrometer screw to give aproportional movement to the control device based upon the relativepitches of the screw threads of the intermediate screw and themicrometer screw.v

Further objects and advantages of my invention will appear from thefollowing disclosure of a preferred form of embodiment thereof taken inconnection with the attached drawing, illustrative thereof, in which: 5

Fig. l is an elevational view with parts in section of a pump providedwith the preferred form of variable volume control.

Fig. 2 is a plan View of the device shown rin Figure l.

Although my invention has general application, :It has especialadvantage in connection with a positive displacement rotarypump such asthat generally illustrated in the Cornell patent referrea to and that ofthe type commonly made by the Yale and Towne Manufacturing Company. Insuch a pump the body, generally indicated at I0, contains an operatingchamber (not shown),

in which a rotor and a piston anda shuttle are operated at apredetermined motor speed by means of the shaft II. Although the detailsof construction of thev pump parts are not shown, it is to be understoodthat the shuttle is mounted on a lever or plunger that can slide from aposition concentric with the shaft to a full eccentric position, inwhich the reciprocating motion will be at its maximum. This lever isgenerally indicated at I2, and its position is controlled by the volumecontrol pump plunger Id, which through pin I5 locates the shuttleposition and thereby determines the capacity of the pump.

Normally the volume control pump plunger I4 is held in a predeterminedposition against the force of a spring I6 by means of a screw whichengages the volume control head washer I8. Heretofore this head washerhas been moved directly by the micrometer screw spindle 2D; and, byrotation of the handwheel 25, accurate adjustment of the pump volume wasobtained.

In accordance with my preferred form of ernbodiment of the invention, Iprefer to insert an adapter member and an intermediate screw spindlebetween the micrometer screw spindle 20 and the volume control headwasher |8. This adapter is generally indicated at 2| and includes ascrew threaded portion which screws into the pump under-body 22 andwhich is provided with a screw threaded recess to receive the screwthreaded end of the micrometer barrel 24. The micrometer spindle 20 isthreaded into the barrel 24 and is secured to the handwheel 25 andmicrometer thimble 25a in the usual manner. The micrometer barrel 24 aswell as the micrometer thimble 25a. is provided with the usual decimalscales as indicated at 26 and 21 respectively.

The adapter 2| carries the intermediate screw spindle 29 having thespindle extension 30, which projects into a cylindrical bore 3| in themicrometer spindle extension 29a. Preferably the micrometer spindleextension 20a is slotted to receive a pin 32 or similar coupling whichprojects through the spindle extension 3D so that rotation of thehandwheel 25 will positively turn intermediate screw spindle 29. Screwspindle 29 on its opposite end is suitably attached to the volumecontrol head washer I8 as by means of the stud 33.

The operation of the devi-ce is as follows:

If a thread pitch of the micrometer screw spindle 20 is assumed suchthat it contains ten threads per inch and if a thread pitch of theintermediate screw spindle 29 is assumed such that it also contains tenthreads per inch, any movement of the micrometer handwheel 25 causes anidentical movement of the volume control head washer I8 and, therefore,the volume control pump plunger I4. In such case the adjustment issimilar to that now in common use, and the range of the scales on themicrometer represents the full range of the pump volume.

If, however, it is desired to have the full range movement of themicrometer handwheel 25 cause only a fractional change in the capacityof the pump, an adapter 2| may be substituted in which the intermediatescrew 29 has more threads per inch than the micrometer screw 20. If, forexample, there are twenty threads per inch on screw 29, the movement ofthe micrometer handwheel 25 through its entire range will bring about amovement of the volume control pump plunger I4 through one-half itsrange only.

For blending lubricating oil with standardized pumps, a few standardsize adapters generally suflce inasmuch as the desired capacity of sucha pump may then be limited from to i0 percent, from 0 to 50 percent,from 0 to 662/3 percent, or from 0 to 80 percent as by usingintermediate screws having 100 threads per inch, 20 threads per inch, lthreads per inch, or 12.5 threads per inch when the micrometer screw hasl0 threads per inch.

It will be apparent that this intermediate screw coupling arrangement isavailable for any micrometer adjustment whether it is used with a pump,an electrical device, or other apparatus. It permits a substantiallyfool-proof and simplified setting practice and makes it impossible toaccidentally set a control device in a manner other than that inaccordance with the predetermined proportional ratio although, ifdesired, the adapter can be quickly removed and a substitute introduced.

While I have shown and described a preferred form of embodiment of myinvention, I am aware that modifications may be made thereto; and I,therefore, desire a broad interpretation of my invention within thescope and spirit of the disclosure herein and of the claims appendedhereinafter.

I claim: 1

1. A micrometric adjusting device comprising a body, a manually operableprimary micrometer screw in screw-threaded engagement with said body, anadapter member having a screw-threaded bore, means releasably securingsaid adapter member to said body in a xed relation to the latter, asecondary micrometer screw screw-engaged in said bore of the adaptermember, and a releasable coupling operatively connecting said primaryscrew to said secondary screw and constructed and arranged to key saidscrews together against relative rotative movement and permit one screwto move axially relatively to the other screw; and means for mountingsaid device in a position to dispose said secondary screw in operativerelation to an element to be adjusted for adjustment of said element byturning said primary screw.

2. A micrometric adjusting device comprising a barrel internallyscrew-threaded at one end, a manually operable primary micrometer screwscrew-engaged in said barrel-end, said barrel being externallyscrew-threaded at its opposite end, an adapter body having an internalscrew thread screw-engaged with said externally threaded end of thebarrel to releasably secure it in a fixed relation thereto, said adapterbody having a screw-threaded bore in axial alignment with said primaryscrew, a secondary micrometer screw screw-engaged in said bore andhaving a pitch different from that of said primary screw, a slipjointcoupling between said screws keying them together against relativerotative movement and permitting relative axial movement therebetween;and means for mounting said device in a position to dispose the outerend of said secondary screw in operative relation to an element to beadjusted for adjustment of said element by turning the primary screw.

3. A micrometric adjusting device comprising a barrel internallyscrew-threaded at one end, a manually operable primary micrometer screwscrew-engaged in said barrel-end, said barrel being externallyscrew-threaded at its opposite end, an adapter body having an internalscrew thread screw-engaged with said externally threaded end of thebarrel to releasably secure it in a fixed relation thereto, said adapterbody having a screw-threaded bore in axial alignment with said primaryscrew, a secondary micrometer screw screw-engaged in said bore andhaving a pitch different from that of said primary screw, a, slipjointcoupling betweensaid screws keying them together against relativerotative movement and permitting relative axial movement therebetween,said adapter body having an external screw thread for mounting saiddevice in a position to dispose the outer end of said secondary screw inoperative relation to an element to be adjusted for adjustment of saidelement by turning the primary screw.

GEORGE A. BATE.

